16687687 has 4 divisors (see below), whose sum is σ = 16794136. Its totient is φ = 16581240.

The previous prime is 16687669. The next prime is 16687691. The reversal of 16687687 is 78678661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 78678661 = 571 ⋅137791.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16687687 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 16687687.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16687637) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 52989 + ... + 53302.

It is an arithmetic number, because the mean of its divisors is an integer number (4198534).

Almost surely, 2^16687687 is an apocalyptic number.

16687687 is a deficient number, since it is larger than the sum of its proper divisors (106449).

16687687 is a wasteful number, since it uses less digits than its factorization.

16687687 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 106448.

The product of its digits is 677376, while the sum is 49.

The square root of 16687687 is about 4085.0565479562. The cubic root of 16687687 is about 255.5438195479.

The spelling of 16687687 in words is "sixteen million, six hundred eighty-seven thousand, six hundred eighty-seven".